Wow, that's a mysterious look she's got! Great color combination and contrast, beautiful figure. Also she's very sexy and I love the claws and her outfit! I suppose she's from an online game, right? Great job
I normally just use the standard round brush to blend colours. I use the soft brush for finishing touches sometimes. They are both default brushes that come in any Photoshop program. I have experimented with custom brushes before and I think Thienbao has some nice brushes.
I don't know if it's just me, but compared to her right forearm and left upper arm, her left forearm looks a bit too thin to me. Apart from that this looks really great! I especially like how lush and vibrant the colours look despite being a bit muted, especially around her legs. I like her face better than the official one as well!
Yes, I paint in monochrome and add colours after because I find it easier to get the dark and light values that I want. I also keep one layer that is coloured black on top of all the other layers and set the blending options to saturation. Then I can toggle on and off the visibility of the layer and keep checking the dark and light values in monochrome.
With layers I keep a few things seperate like the lineart, background and a few colour layers. I think its easier to change things if you make a mistake.
hmmmm...painting under the b+w havent thought of that...but i always find it hard to bring out the pictures vibrancy, its always so...dull. oh and as for colours i sometimes find the blending options of the brush fun to play with, since itll drag and implement colours around it. "happy accidents" ;D